Camaro LT1 Z28 Engine Specifications

1970 engine is used as the baseline. 1971 & 72 will be identical except where noted 1971 had compression dropped from 11.0:1 to 9.0:1 by using different pistons and bigger CC cylinder head. 1972 is identical to 1971, except horsepower dropped 10 and rating was changed from GROSS HP to NET HP. This engine was incompatible with Air Conditioning. You could NOT order a vehicle equipped with this engine along with Air Conditioning. This is why NO Z28 prior to 1973 has air conditioning.

1970 - 1972 LT-1 Engine 1970 Z28 Engine - LT1 360hp (gross) Casting # GM P/N Description Block 3970010 4 bolt main, suffix codes: CTB, CTC Crankshaft 330550 Forged steel Heads 3927186 63.995 cc, 2.02/1.6 valves, screw in studs & guide plates Cam 3972182 3972178 symbol: (1) square Solid lifter - 0.458(I)/0.484(E) lift, 317I/346E duration Pistons Domed type - yields 11.0:1 compression Intake 3972110 Carb (A/T) 3972120 Holley List 4490, 780cfm , 4150 series - 4BBL Carb (A/T) 3972122 Holley List 4554, 780cfm , 4150 series - 4BBL w/NB2 (Calif) Carb (M/T) 3972121 Holley List 4555, 780cfm , 4150 series - 4BBL Carb (M/T) 3972123 Holley List 4489, 780cfm , 4150 series - 4BBL w/NB2 (Calif) LH Exhaust 3942527 2.026", Rear Outlet, AIR RH Exhaust 3946826 1.96", Rear Outlet, AIR Distributor 1112019 single point w/RFI Alternator: Delcotron 37 Amp, part # 1100837 Water Pump: 3953692 crank pulley: 9956668 coded CG Deep Groove Water Pump Pulley: 3995647 coded AP Power steering Pulley: last four #'s 1105 Note: Rods: LT1 "pink" rods. 5.7", 6th design, forged steel, shot peened, magnafluxed, heat treated, high RPM rod bolts and expensive. Intake 3972116 listed as service replacement manifold. 1971 Z28 Engine - LT1 330hp (gross, 275hp NET) Casting # GM P/N Description Block 3970010 4 bolt main, suffix codes: CGP, CGR Crankshaft 330550 Forged steel Heads 3973487 75.47 cc, 2.02/1.6 valves, screw in studs & guide plates Cam 3972182 3972178 symbol: (1) square Solid lifter - 0.458(I)/0.484(E) lift, 317I/346E duration Pistons Flat w/valve relief - yields 9.0:1 compression Intake 3959594 Carb (A/T) 3989022 Holley List 4800, 780cfm , 4150 series - 4BBL Carb (M/T) 3989021 Holley List 4801, 780cfm , 4150 series - 4BBL LH Exhaust 3989041 Rear exit, log type w/AIR, 2.026 outlet RH Exhaust 3986330 Rear exit, log type w/AIR, 1.96 outlet Distributor 1112049 Manual Trans, RFI, single point w/vacuum Distributor 1112074 Auto Trans, RFI, single point w/vacuum Alternator: Delcotron 37 Amp, part # 1100837 Water Pump: 3957170 Cylinder head has swirl polished valves and chrome valve stems. Alternate cylinder head was 3986316 (unverified). 1972 Z28 Engine - LT1 255hp (net) Casting # GM P/N Description Block 3970010 4 bolt main, suffix codes: CKS, CKT Crankshaft 330550 Forged steel Heads 3998916 76.18 cc, 2.02/1.6 valves, screw in studs & guide plates Cam 3972182 3972178 symbol: (1) square Solid lifter - 0.458(I)/0.484(E) lift, 317I/346E duration Pistons Flat w/valve relief - yields 9.0:1 compression Intake 3959594 Carb (A/T) 3997788 GB Holley List 6238, 780cfm , 4150 series - 4BBL Carb (M/T) 3999263 GA Holley List 6239, 780cfm , 4150 series - 4BBL LH Exhaust 3989041 Rear exit, log type w/AIR, 2.026 outlet RH Exhaust 3986330 Rear exit, log type w/AIR, 1.96 outlet Distributor 1112095 Manual Trans, RFI, single point w/vacuum Distributor 1112049 Auto Trans, RFI, single point w/vacuum Distributor 1112153 2nd design - M/T, single point w/vacuum & ECC Distributor 1112156 2nd design - A/T, single point w/vacuum & ECC Alternator: Delcotron 37 Amp, part # 1102454 Water Pump: 6263701 unverified but alternate head casting #'s include: 3973487, 3973487X, & 3998993